<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<%
String str=null;
pageContext.setAttribute("name",str);
%>
${empty str}<br>
<%
    String str1="";
    pageContext.setAttribute("name",str1);
%>
${empty str1}<br>
<%
    String[] str3={};
    pageContext.setAttribute("name",str3);
%>
${empty str3}<br>

<%pageContext.setAttribute("gender","man");%>
<input type="radio"value="man"name="gender" ${gender=="man" ? "checked":"" }>/男
<input type="radio"value="woman"name="gender" ${gender=="woman" ? "checked":"" }>/女

</body>
</html>
